Impact absorbing apparatus



J. T. SMITH IMPACT ABsoRBING APPARATUS Filed oct. 5 k1966s Dec. 23, 1969 United States Patent O 3,485,385 IMPACT ABSORBING APPARATUS James T. Smith, Wilmette, Ill., assignor to Keystone Industries, Inc., a corporation of Delaware Filed Oct. 3, 1966, Ser. No. 583,797 Int. Cl. B61g 9/14, 9/16 U.S. Cl. 213-43 5 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to an impact absorbing apparatus and particularly to an improved impact absorbing apparatus for railway rolling stock.

In the coupling of railway rolling stock, there is a problem in protecting the load or lading against damage from impacts given to a fully or partially loaded freight car. The character of the lading itself usually dictates the best manner in which it should be secured in a freight car. Some of the securing techniques provide for a controlled and limited movement of the load within the car to absorb the coupling or similar impact without damage to the load.

A draft gear connected to the coupler absorbs a part of the shock, but its effectiveness is limited by the severe limitation on the movement of the coupler relative to the remainder of the car. This movement is approximately 2% inches so as to minimize the amount of slack in a train that should be taken up on starting and absorbed on stopping.

In a conventional draft gear it has been the practice to use cushioning or friction springs for withstanding forces such as impact applied to a coupler. It has also been attempted by more modern-day draft gear designers to construct a hydraulic draft gear and interrelate it with a railroad car to afford the desired energy dissipation. However, such practices have not afforded complete cushioning.

In such systems there is frequently a metal to metal contact at the limit of bul movement. The present invention prevents such contact, and the consequential banging, jarring and possible damage, by insertion of an elastomer in the impact absorbing device. The elastomer is normally in an uncompressed condition, Before the end of permitted movement the elastomer is contacted and cushions the iinal travel of the device.

It is, therefore, an object of this invention to provide a unique hydraulic draft gear for an impact absorbing apparatus which resists buff action.

It is a further object of this invention to provide a slidable member with an elastomer to cushion the final travel of an impact absorbing apparatus.

It is a further object of this invention to provide an impact absorbing apparatus which is capable of mounting in a standard coupler and unite said coupler with an impact absorbing apparatus in a novel way so that buif movement of said coupler etfects operation of the impact absorbing apparatus and terminates such movement without metal to metal contact.

Other objects and features of this invention will more fully appear from the following detailed description taken in connection with the accompanying drawings which illustrate a single embodiment thereof and in which FIG. 1 is a vertical sectional view of a draft gear of the invention;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a sectional view taken along the line 3 3 of FIG. 1;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 1; and

FIG. 5 is a partial view of the right end of the mechanism shown in FIG. 1 with a conventional coupler member.

In accordance with the features of this invention there is provided a railroad draft gear comprising a casting 10 to which a conventional E-type coupler 10a is adapted to be connected. Casting 10 is slidably mounted in a housing 11 and connected through a fitting 12 to a piston rod 14. Mounted within the housing 11 is a hydraulic cylinder 16 in which a piston 18 is movable.

The piston 18 expels hydraulic duid through the openings 20 into a reservoir 22 surrounding the cylinder and the differential volume displacement is taken up by a series of neoprene accumulators 24. This type of mech- ICC anism is disclosed in an application of James T. Smith entitled Impact Absorbing Apparatus Ser. No. 395,390, led Sept. 10, 1964, now Patent No. 3,332, 364.

A rod 26 extends from the opposite end of the cylinder and has a plate 28 secured to it to compress a spring 30 upon the impact or buff movement. The spring 30 coacts with the hydraulic mechanism.

A group of urethane cushions 32 are interposed between a metallic plate 34 and an outer metallic end 48 of the cylinder 16. End plate 36 is mounted on the piston rod 14 for slidable movement therewith.

The housing 11 is mounted on a base 42 attached to a center sill of a railroad car (not shown). Surrounding the hydraulic cylinder 16 is the cylinder end member `48 through which hydraulic fluid passes by means of ports 44 to the neoprene accumulators 24.

In impact absorbing apparatus such as this there is a substantial amount of contact between metal parts at the conclusion of buff movement. Thus, the inner end of the casting 10 would bang against the end of the cylinder 16 when complete buff travel had been accomplished. This results in substantial jarring and also in potential damage to the parts.

In operation the urethane cushions 32 interposed between the plate 34 and the outer end of the cylinder 16 are normally in an uncompressed condition and about an inch and an eighth from the end of the permitted movement of the piston rod 14. The end 36 of the casting 10 contacts the plate 34 and compresses the urethane cushions 32 thus absorbing the impact and gradually taking over then from the hydraulic cushioning alorded by the cylinder 16 to the mechanical` cushioning afforded by the elastomers or urethane cushions 32.

In normal position the spring 30 holds the plate 28 in the extreme left position. Should the car receive an impact from the right, the casting 10, piston rod 14, rod 26, plate 28 and the end plate 36 will be moved to the left. The end plate 36 in moving to the left engages the elastomers 32 through the plate 34 thereby increasing the resistance to piston travel leftwardly and results in a greater absorption of the impact. This is subsequent to compression of the spring 30 and compression of the ne-oprene accumulators through the cylinder end mem ber 48. The elastomers thus absorb the energy of the final leftward movement of the device. The hydraulic fluid is expelled through the openings 20 by the piston 18 and passes the reservoir 22 through the ports 44 of the cylinder end member 48 to compress the donut-like rings 24 against the pressure of the air therein.

After the impact has been absorbed, the system returns to normal, the spring 30 expands moving the rod 26 and piston rod .14 to the right. As this occurs the piston 18 moves to the right, hydraulic fluid re-enters the hydraulic cylinder 16 relieving the pressure -on the neoprene accumulators 24. The neoprene accumulators 24 expand to their normal position expelling fluid from the reservoir 22 through the openings 20 and into the hydraulic cylinder 16.

A similar impact absorbing apparatus would be located on the left side of the railroad car in order to absorb impact from the left.

While I have shown and described a preferred embodiment of my invention, it will be apparent that numerous variations and modifications thereof my be made without departing from the underlying principles ofthe invention. I therefore desire, by the following claims, to include within the scope of the invention all such variations and modifications by which substantially the results of my invention may be obtained through the use of substantially the same or equivalent means.

I claim:`

1. In an impact absorbing apparatus a coupler, a cylinder housing, a metallic cylinder end member, a slidable member mounted within said cylinder housing and attached to said coupler, and extending through said cylinder end member, spring means biasing said slidable member in a first position, a metallic end plate mounted on said slidable member, and elastomer means mounted within said housing between said end plate and the cylinder end member whereby on impact said coupler drives said spring from said first position to a second position intermediate said first position and the maximum extent of longitudinal travel of said slidable member, said elastomer means being contacted by said end plate at said second position, whereby said elastomer means absorbs the terminal impact and prevents metal to metal contact between the end plate and the cylinder end member.

2. An impact absorbing apparatus in accordance with claim 1 wherein said elastomer means are urethane cush ions.

3. An impact absorbing apparatus in accordance with claim 1 wherein said slidable member yoperates hydraulic means which coacts with said spring means to cushion buff movement.

4. An impact absorbing apparatus in accordance with claim 1 wherein said housing has hydraulic means including a piston operated by said slidable member such that from the first position said hydraulic means opposes movement of said piston, accumulator means, said piston being mounted within a tubular hydraulic cylinder having openings disposed longitudinally of said piston whereby longitudinal movement of said slidable member causes movement of said piston to displace hydraulic tluid which thereupon acts on said accumulator means.

5. An impact absorbing apparatus in accordance with claim 4 wherein said accumulator means are hollow neoprene rings.

References Cited UNITED STATES PATENTS 3,217,897 11/1965 Peterson 213-43 3,227,288 1/1966 Mulcahy et al. 213-22 3,332,364 7/1967 Smith 213--43 X DYRAYTON E. HOFFMAN, Primary Examiner U.S. Cl. XR. 213-8 

